The re-use of used motor oil has traditionally been limited to the burning of used motor oil in factories or manufacturing plants as a means to generate heat and/or fire boilers. However, recent changes by the U.S. Environmental Protection Agency to the rules governing the burning of used motor oil have severely restricted this practice. As a result, much of the used motor oil previously burned now must be disposed of as waste or repurposed in some other way.
Some attempts have been made to convert the used motor oil into higher grade fuels. This typically includes attempts to “re-crack” the used motor oil in a refinery system or chemically change the oil by adding various reactants. Neither method has proven to be economically viable and/or to produce sufficient amounts of higher grade fuels.